Epson RS-353, Service Manual

Page: 35 / 130

(2) Outline of function
* The Interlock switch is accordingly work with the lamp cover at the bottom of main
chassis. It is normally at the ON position. It will shut the AC power by opening the
lamp cover.

Cable connected to the connector CN 505 on the main board is the signal line to
indicate the conditions of two fans (exhaust fan and inhale fan) which are connected
to the connector CN
502 on the main board. They will shut the power to the
light source lamp for preventing over heat in case of the fan malfunctionally stops
rotating.

The filter/rectification circuit work to neglect noise on the AC line and generate DC
voltage for the regulator.
The regulator generates the various level of DC voltage as shown in the below table in
the switching regulator. The regulator detects the voltage output level at the line
and feed back to the switching circuit to maintain the output level stable regardless the
load variation.

The inhale fan is built for exhausting the heat generated in the power supply unit. The
heat exhausted by the inhale fan will be exhausted outside by the exhaust fan which is
connected to the’connector CN 503 on the main board.
(3) Pin assignment
Pin No. I/O Signal
1 IN Lamp on/off
2-9
Ground
7 OUT
a
OUT
9 OUT
O U T
2-5